The present invention relates to a masonry wall system and, more particularly to a retaining wall having post tensioning elements and an optional extended wall.
The utilization of masonry fences as retaining walls is well known in the prior art. The significant pressures caused by the soil bearing upon the wall surface requires prior art masonry walls to incorporate a significant amount of steel in the form of re-enforcing bars extending through the voids in the masonry block into a footer. A variety of techniques have been used in the prior art in an attempt to strengthen the wall and to provide sufficient resistance to the pressure caused by soil pressing against one side of the wall; these techniques are usually complicated and always expensive. Some prior art techniques have incorporated post-tensioning wherein courses of block have been compressed with respect to each other and the compressed courses are then secured in some manner to a foundation. These latter techniques usually require expensive installation provisions for appropriately supporting the compressed courses on the designated footer.
The present invention incorporates a masonry retaining wall structure that utilizes a footer, foundation or conventional retaining wall for supporting a retaining wall""s first course of masonry block. Post-tensioning rods are imbedded in the footer concrete. The post-tensioning rods extend upwardly essentially vertically from the footer. A plurality of courses of masonry block are then placed on the footer with the respective post-tensioning rods extending through the cells therein. The post-tensioning rods extend upwardly beyond the next to the top course of the masonry block. An elongated clamping plate extends across the cells of the masonry blocks in the next to the top course of blocks. The plate has a plurality of openings therein to permit the passage of the ends of a respective post-tensioning rods. The end of each of the post-tensioning rods is threaded to accept a nut which is placed on the rod and threaded to engage the clamping plate. Predetermined tension is placed on the respective post-tensioning rods. A top course of masonry blocks may be placed on the plate with the cells therein receiving the threaded rod ends engaging the nuts and being filled with grout. Horizontally aligned rebar(s) may be placed in the top course to tie in the masonry blocks with one another and form a bond beam having its top surface in general alignment with the grade of the said being retained. To build thereon an extended wall, a threaded coupling is attached to one or more of the threaded rod ends. The threaded ends of further post-tensioning rods are threadedly engaged with respective couplings to extend upwardly through the top course subsequently formed as a bond beam and into the extended wall supported upon the retaining wall. The upper ends of these further post-tensioning rods are secured to a plate resting on a course and a nut draws these rods toward such plate to place them in tension.
A primary object of the present invention is to provide a masonry retaining wall system that may be constructed relatively inexpensively and nevertheless provides sufficient strength to resist the forces of the soil pressing against one side thereof.
Another object of the present invention is to provide a retaining wall system wherein a very high strength wall retains the soil and provides a base upon which a less expensive upwardly extended wall may be supported.
Still another object of the present invention is to provide a retaining wall system that can be inexpensively constructed to provide all of the advantages of a conventional retaining wall system and to provide an economical retaining wall for supporting a fence extending beyond the grade level of the soil being retained by the retaining wall.
Yet another object of the present invention to provide a retaining wall system incorporating post-tensioning to compress the courses of block within the retaining wall against a footer, a foundation or a conventionally constructed retaining wall and provide a significant cost reduction in the construction of the complete retaining wall.
A further object of the present invention is to provide for post-tensioning of an upwardly extended wall supported upon a retaining wall incorporating post-tensioning to exert compression forces between the upwardly extending wall and the retaining wall.
A still further object of the present invention is to provide post-tensioning intermediate a footer (or foundation or conventional retaining wall) an intermediate retaining wall and an extended wall extending upwardly from the intermediate retaining wall.
A yet further object of the present invention is to provide a method for post-tensioning a retaining wall.
A yet further object of the present invention is to provide a method for post-tensioning an extended wall supported by an intermediate retaining wall with a conventional footer, foundation or retaining wall.
The objects will become apparent to those skilled in the art as the description of the invention proceeds.